Distribution of iduronate 2-sulphate residues in heparan sulphate. Evidence for an ordered polymeric structure.

2.50
Hdl Handle:
http://hdl.handle.net/10541/104750
Title:
Distribution of iduronate 2-sulphate residues in heparan sulphate. Evidence for an ordered polymeric structure.
Authors:
Turnbull, Jeremy E; Gallagher, John T
Abstract:
The structure of human skin fibroblast heparan sulphate has been examined by depolymerization with heparinase, which specifically cleaves highly sulphated disaccharides of structure GlcNSO3 (+/-6S)-alpha 1,4IdoA(2S) [N-sulphated glucosamine (6-sulphate)-alpha 1,4-iduronic acid 2-sulphate]. Heparan sulphate contained only a small proportion (approximately 10%) of linkages susceptible to this enzyme. The major products of depolymerization with heparinase were large oligosaccharides with an average molecular mass of 10 kDa (dp approximately 40, where dp is degree of polymerization; for disaccharides, dp = 2 etc.) as assessed by gel filtration on Sepharose CL-6B, compared with a molecular mass of 45 kDa (dp approximately 200) for the intact chains. The large heparinase-resistant oligosaccharides were highly susceptible to depolymerization with the enzyme heparitinase, which cleaves heparan sulphate in areas of low sulphation, where N-acetylated disaccharides [GlcNAc-alpha 1,4GlcA (N-acetylglucosaminyl-alpha 1,4-glucuronic acid)] are the predominant structural unit. Further analysis of the location of the heparinase cleavage sites indicated that they were predominantly found in a central position in GlcNSO3-alpha 1,4IdoA repeat sequences of average length four to seven disaccharides (dp 8-14). These results indicate that heparinase cleaves heparan sulphate in approximately four or five N-sulphated domains, each domain containing a cluster of two or three susceptible disaccharides; the domains are separated by long N-acetyl-rich sequences that are markedly deficient in sulphate groups. On the basis of these findings a model is proposed which depicts heparan sulphate as an ordered polymeric structure composed of an alternate arrangement of sulphate-rich and sulphate-poor regions. The sulphate-rich regions are likely to be flexible areas of the chain because of their high content of the conformationally versatile IdoA and IdoA(2S) residues. The model has important implications for the biosynthesis and functions of heparan sulphate.
Affiliation:
Department of Clinical Research, University of Manchester, Christie Hospital and Holt Radium Institute, U.K.
Citation:
Distribution of iduronate 2-sulphate residues in heparan sulphate. Evidence for an ordered polymeric structure. 1991, 273 ( Pt 3):553-9 Biochem. J.
Journal:
Biochemical Journal
Issue Date:
1-Feb-1991
URI:
http://hdl.handle.net/10541/104750
PubMed ID:
1996955
Type:
Article
Language:
en
ISSN:
0264-6021
Appears in Collections:
All Paterson Institute for Cancer Research

Full metadata record

DC FieldValue Language
dc.contributor.authorTurnbull, Jeremy Een
dc.contributor.authorGallagher, John Ten
dc.date.accessioned2010-06-11T15:54:03Z-
dc.date.available2010-06-11T15:54:03Z-
dc.date.issued1991-02-01-
dc.identifier.citationDistribution of iduronate 2-sulphate residues in heparan sulphate. Evidence for an ordered polymeric structure. 1991, 273 ( Pt 3):553-9 Biochem. J.en
dc.identifier.issn0264-6021-
dc.identifier.pmid1996955-
dc.identifier.urihttp://hdl.handle.net/10541/104750-
dc.description.abstractThe structure of human skin fibroblast heparan sulphate has been examined by depolymerization with heparinase, which specifically cleaves highly sulphated disaccharides of structure GlcNSO3 (+/-6S)-alpha 1,4IdoA(2S) [N-sulphated glucosamine (6-sulphate)-alpha 1,4-iduronic acid 2-sulphate]. Heparan sulphate contained only a small proportion (approximately 10%) of linkages susceptible to this enzyme. The major products of depolymerization with heparinase were large oligosaccharides with an average molecular mass of 10 kDa (dp approximately 40, where dp is degree of polymerization; for disaccharides, dp = 2 etc.) as assessed by gel filtration on Sepharose CL-6B, compared with a molecular mass of 45 kDa (dp approximately 200) for the intact chains. The large heparinase-resistant oligosaccharides were highly susceptible to depolymerization with the enzyme heparitinase, which cleaves heparan sulphate in areas of low sulphation, where N-acetylated disaccharides [GlcNAc-alpha 1,4GlcA (N-acetylglucosaminyl-alpha 1,4-glucuronic acid)] are the predominant structural unit. Further analysis of the location of the heparinase cleavage sites indicated that they were predominantly found in a central position in GlcNSO3-alpha 1,4IdoA repeat sequences of average length four to seven disaccharides (dp 8-14). These results indicate that heparinase cleaves heparan sulphate in approximately four or five N-sulphated domains, each domain containing a cluster of two or three susceptible disaccharides; the domains are separated by long N-acetyl-rich sequences that are markedly deficient in sulphate groups. On the basis of these findings a model is proposed which depicts heparan sulphate as an ordered polymeric structure composed of an alternate arrangement of sulphate-rich and sulphate-poor regions. The sulphate-rich regions are likely to be flexible areas of the chain because of their high content of the conformationally versatile IdoA and IdoA(2S) residues. The model has important implications for the biosynthesis and functions of heparan sulphate.en
dc.language.isoenen
dc.subject.meshAdult-
dc.subject.meshCarbohydrate Sequence-
dc.subject.meshCells, Cultured-
dc.subject.meshChromatography, Gel-
dc.subject.meshFibroblasts-
dc.subject.meshHeparan Sulfate Proteoglycans-
dc.subject.meshHeparitin Sulfate-
dc.subject.meshHumans-
dc.subject.meshIduronic Acid-
dc.subject.meshMolecular Sequence Data-
dc.subject.meshProteochondroitin Sulfates-
dc.subject.meshSkin-
dc.titleDistribution of iduronate 2-sulphate residues in heparan sulphate. Evidence for an ordered polymeric structure.en
dc.typeArticleen
dc.contributor.departmentDepartment of Clinical Research, University of Manchester, Christie Hospital and Holt Radium Institute, U.K.en
dc.identifier.journalBiochemical Journalen
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